Separating device for lead storage batteries



2 Sheets-Sheet Fig@ c. .A w. FHWA SEPARATING DEVICE FOR LEAD STORAGE BATTERIES Filed My le, 192e OOOOOOOO OOOOOOOO OOOOOOOOOOO Fil g CNWAA c. .11. w. PHY

SEPARATENG DEVICE EOE LEAD sToEAEE BATTERIES Filed May 18. 192e I z SEMES-sheet 2 FWS.

ttl

.mmv cron unav, or ris, nnen.

` it bhTlUltltEl-IDDFWTE FUR JLFFD STORAGE BATTERIES.

duplication tiled lltay lt, that, Ferial No. 110,035, and in France May 525, 1925.

- ln lead storage batteries, the electrolyte encloses -oxygen the presence ot which is due, on the one hitnd, to the contact ot theelectrolyte `with the outer air the oxygen ot which u dissolves at the surface ot this electrolyte and,

on the other hand, to the evolution ot oxidizing bodies vvhich are ditlused in the mass ci the electrolyte by the active material otthe positive plates, when it slowly decomposes. The simultaneous action oi the electrolyte v and ot the oxygen it contains, upon the negative plates oit lead storage batteries has for etl'ect ot producing a loss ot charge ot the latter vvhen they are in open circuit and, be-

ia sides, the sulphation ot thesestorage batteries vvhen they are lett to rest after discharge.

lt has been proposed to protect the negative plates ot lead storage batteries against au the oxidizing products evolved bythe positive plates, by diaphragms or separating devices, but the devices used up to this day ensure but an impertect protection, as theyA it'orm only a partial obstruction to the pasau sage ot' the oxidizing products evolved by the positive plates and cannot prevent the oxygen ol" the air having access to the negative plates.

The present invention has tor object an improvement in lead storage batteries and tu consisting in the application ot a separating device adapted to ensure the protection oil-'the negative plateson the one hand, against the oniing products evolved by the positive plates and on the other hand, against thev au oxygen' ot the air tor the purpose oit maintaining the charge ot; these storage batteries, vvheii they are at rest, and et preventing their sulphation; .I

lllioreover, by its special constitution, this m Separating device allows an easy circulation ot the electrolyte about the negative plates and thus prevents the stagnation oit the exhausted liquid about the negative plates vvhichstagnation causes, in the' case oit very,-

'is open at both ends so as Vto permit, on the one hand, the circulation ot the electrolyte in the space reserved between the said sheath andthe negative plate and, on the other hand, the evacuation of the hydrogen which evolves on each ot the negative plates during chargmg.

(b) rlhe arrangement above the 'negative plates ci. a protector so devised as to prevent the access of the oxygen ot the outer air upon the upper part ot',y these plates, Whilst permitting the evacuation to the exterior of the hydrogen which' evolves on the said plates.

Several forms ot carrying out vthe invention will be described hereinafter, by way ot example, with reference to the accompanying dravving in which: y

Figs. 1 to 3 illustrate a form of carrying out the invent-ion applied to a storage battery element having tvvo plates; Fig. l shovvs the-storage battery element in cross vertical section; Fig. is a plan View; Fig. 3 is a horizontal section made according to line A-A ot Fig. 1.

Fig. 4 is a horizontal section of a modification.

Fig. 'illustrates in cross vertical section another form ot construction applied to a storage battery with free electrolyte.

Fig. 6 shows, also in cross vertical section, another mode ot construction applied to a storage battery in which the electrolyte is immobilized.

As shovvn in Figs. l to 3, the storage'battery element comprises a vessel a containing two plates: a positive plate and a negative plate c constituted in the ordinary manner, and the electrolyte in vvhich these plates are placed. i

The negative plate c is completel surrounded by a sheath d' constituted, torl instance, lby a -sheet of parchment paper or ot pure cellulose chemically prepared, such as that vused tor the manufacture ot artiiicial au intense outdovvs, t'or instance in the case ot the starting ot motor cars, the polarization ot the storage hattery.. Y

The separating'device, lorg the subject-matter ot the invention, is characterized au by the tvvo tollog points.

Mld

la) the protection oit each negative plate against the oxidizing products evolved by the positive plates, by means ot a sheath vvhich is impervious to gases and completely suruu rods the negative plate ,fzbesides, this sheath ot the negative plate c andthe sheath d tor the tree circulation ot the electroll te; this interval is maintained by any suitab e device,

' tor instance by the interposition, betvveen each ot the t'aces ot the plate c and sheath al, ot a ltd stt)

waved perforated sheet e, made of insulating material and on which the said sheath Z is stretched.

The upper part of the sheath l is covered by a bell f entering the electrolyte so as to constitute a liquid joint about this sheath, this bell, which can be made of insulating material, such as ebonite or Celluloid, i-s carried, for instance, by the tail end g of the plate c.

By means of this device, at the end of the charging of the storage battery, the hydrogen, which evolves at the negative electrode, is collected under the bell f and can subsequently be freely evacuated through the interval existing between the lower edge of this bell and the periphery of `the upper part of the sheath d; it results therefrom that after charging the electrolyte, which surround-s the negative plate, is covered with hydrogen which disappears gradually, as noticed by the inventor during the discharge by dissolving in this electrolyte. In these conditions the negative plate is completely protected against the oxygen of the air.

Besides, the sheath prevents the oxygen bubbles which slowly evolve from the positive plate from having access to this negative plate.

Finally, during discharge, when the electrolytic liquid rises above the upper edge of the sheath (Z, for instance up to the level X-X, a circulation of this electrolyte is pro duced, owing to the diminution of density of the electrolyte during discharge. in the direction of the arrows shown in Fig. I, in the free space comprised between the plate c and the sheath d; this causes a constant admission of fresh liquid on to the negative plate c, this liquid entering through the lower open end of the sheath d.

From the foregoing it will be seen that this separating device completely prevents the admission of oxygen on to the negative plate, and that the bell f, closed at its lower part by a liquid joint, operates as a valve preventing the entrance of the outer air into the space situated above the plate c, and permitting the issue of the hydrogen evolving from the negative electrode during charging.

Fig. 4 shows in horizontal section, a modification in which the separating sheath is constituted by two wooden partitions d1 similar to those used in starting batteries for motor cars, and two side couplings made of ebonite, Celluloid or any other suitable material, fitting on these two partitions d1.

The walls (Z1 are provided, on their inner face, with ribs d3 adapted to maintain, between the said partitions and the negative plate c, the interval permitting the circulation of the electrolytic liquid surrounding this plate, as previously explained.

' The side couplings d2 are glued upon the 'partitions di, for instance by a celluloid glue,

so as to ensure the closing of the sheath on its sides.

This separating sheath is covered, as previously stated, by a bell preventing access of the oxygen of the air and retaining the hydrogen during charging, whilst permitting the evacuation of the excess of this gas.

In the form of construction illustrated in Fig. 5, each of the negative plates c is completely surrounded, as above stated, by a sheath (l constituted, for instance, by a sheet of parchment paper or of pure cellulose chemically prepared, or by any other spongy material having suiiciently tine pores so that after imbibition of the liquid it should be impervious to gases.

This sheath d, open at both ends, emerges at its upper part above the level of the electrolyte L.

Above this electrolyte la, ioats a layer of heavy oil z', the level of which is above the upper end of the sheath (Z surrounding lthe negative plates.

This layer of oil z' prevents access of the air in the electrolyte and to the upper part of the negative plates c, whilst permitting the evacuation of the gases which evolve from the electrodes; the hydrogen which evolves from the negative plates, during charging. rises through the electrolyte in the free space reversed between each of these plates and its separating sheath, then passes through the layer of heavy oil z' and escapes into the air; likewise, the oxygen evolving from the positive plate b escapes through the layer of oil z' without coming in contact with the negative plates c protected by their sheath d.

This method of carrying out the invention, which is of a very simple construction, is particularly applicable to stationary storage batteries.

In the form of construction illustrated in Fig. 6 which relates to a storage battery in which the electrolyte is immobilized, the negative electrodes c surrounded by their separating sheaths d, as previously stated, are arranged at a level lower than that of the positive electrode b so that the upper part of each of the negative plates is covered with a layer of immobilizing material 71 sufficiently thick for preventing access of the air which might enter through the orifices Z provided in the insulating obturating layer m and adapted to prevent the evacuation of the gases evolvinof within the storagebattery.

2For avoiding the action of oxygen upon the tail ends of the negative plates n, which are not protected by the separator d, it is convenient to varnish these tail ends with a varnish which is not attacked by the acid, or to cover them with a rubber tube.

As in the preceding cases, the separating sheaths d, open at both ends, permit the cireulation, of the electrolyte along the walls of the negative plates c and prevent any lateral lli() lill iuaaaaaa access upon the latter el the oxygen evolved trom the positive plate b.

Moreover, the layer ol immobiliaing material interposed between the positive plate 5 and the sheaths al prevents any direct contact of this plate with the said sheaths and, consequently, any risk olE deteriora-tion ol the latter. c

Finally, the layer el immobilizng material situated below the positive platev b retains the active material falling trom this plate and prevents this lalling. active mat-erial from reaching thelower opening etv the sheaths 0l surrounding the negative plates c. This type of storage battery, which is yeasily transportable, without risk ol projection of acid, is particularly applicable on vey hicles, either'tor traction or lighting purimpregnationby the liquid in which it is a Vmerged is impervious to gases, Ya partitiiuaA p The above described devices are applicable to all systems olf leadstorage batteries having vertical plates, whatever may be the number ot positive and negative plates composing the storage battery.

l. A separating device lor the protection ot the negative plates/'ol lead storage batteries against the oxidizing productswhich become disengaged trom the. positive plates' and against the oxygenot the air, comprising a.

protecting sheath surrounding the negative `plates and open at the opposite ends, said sheath cpnsisting ot a material whichV alter wall arranged between the protecting sheath and the laces ol the negative plates in vorder `ative seal. p p jiy- Y eloregoing el my separating device tor lead storage batteries,W sied by me this 7th jday et alb 2. il separating device tor the protection ot"I the negative plates ol' lead storage batteries against the oxidizing product discharged by the negative platesand against the oxygenel the air, comprising a protecting sheathing surrounding the negative plates and open at the opposite ends, said sheathing consisting et a material which alter the impregnation with the liquid in which it is immerged, be-

comes impervious to` gases, a partition wall inserted between the said protecting sheath and the laces el the negative plates to term between the walls ot said casing and the'plates bill a tree space lor the circulation ol the e'lectrolyte around said negative plates, a bell adapted to cover the upper part ot the casing dll and the negative plates and immerging into lthe 'electrolyte in order to close said bell at the base by a liquid seal and to lorm in such a maer a protecting means against the admission oil the oxygen ol the outer air to the negative plate and permitting the esca'pin` et the hydrogen which is termed on said ne plate, to the outside through the liquid llpril, limb. U l il 

